Indoor Environmental Quality is any factor of the built environment that affects the health and comfort of building occupants. Indoor Environmental
Quality includes but is not limited to the following[1] :
  • access to natural light
  • artificial lighting
  • connection to the outdoors
  • acoustics
  • thermal comfort
  • occupant control
  • air quality
Nowadays, people spend more time indoors than outdoors, and air pollution is 25% higher indoors than outdoors.[2] Therefore, improving indoor environmental quality not only impacts the well-being of building occupants physically, socially, and psychologically, but also decreases unnecessary building resources.

Improvement


Socially, good indoor environmental quality helps sustainability of an inhabitant in numerous ways. In many cases, the first thing people are concerned about when they start designing and building a house is the cost of it. However, they do not realize if they would think about first providing occupants with good indoor environment, the building would give back more in the long run economically. [3] Buildings that are sustainable are those that satisfy
occupant comfort and therefore improve productivity, increase energy efficiency, which is environmentally friendly, and allow easy operations.

Historical Background


For years, indoor environmental quality has increasingly become a problem, but little development has been made to it. For about 100 years, indoor air quality was under a lot of attention until 1960 hit when outdoor pollution became a more prominent problem.[4] In developing countries, indoor quality is polluted because of unvented residual biomass in the air, killing 2 million people a year, whereas in developed countries, indoor quality is polluted because of indoor radon intake and environmental tobacco smoke exposure, although smoke exposure has been decreasing. The mystery about breathing air was not solved until the 1800s when scientists finally understood that humans need to breathe air not only for its coolness but also for its substances. Other aspects of indoor environmental quality were not brought to attention until much later. The development and improvement of indoor environmental quality was difficult and slow.

1. Government finds it difficult to put regulation on indoor environmental quality control, because it would violate the privacy issue.[5]
2. There are no solid numbers to prove the economic damage of bad indoor environment.[6]
3. There are few studies being done on indoor environmental quality, which are only focusing on single discipline.[7]

Available Variations


Different variations of improving air quality[8]
  • Keep floors clean
    • Use a vacuum to suck up all the chemicals and dust, use mops to clean up the residue, and use mats to keep the dirt and pesticides out.
    • Advantage: easy to accomplish with easily accessible tools
    • Disadvantage: hard to keep it up fruquently
  • Keep a healthy level of humidity
    • Make sure to allow enough air circulation during cooking, using a dish washer to keep mold from growing
    • Advantage: save electricity bill by keeping down the humidity
    • Disadvantage: tedious work to do
  • Make your environment an non-smoking zone
    • Cigarette smoke contains more than 4,000 chemicals, so stopping the spread of smoke is crucial for a healthy air quality.
    • Advantage: indoorenvironment changes drastically
    • Disadvantage: in other parts of the world, non-smoking indoors is not a restriction.
  • Test for radon
    • Radon is the second leading cause for lung cancer, checking and maintaining a reasonable level of radon in either new or old home is important.
    • Advantage: best way to get an accurate reading regarding the radon in buildings
    • Disadvantage: could be a little costly
  • Smell good naturally
    • Most of the chemicals in fragrance are not tested, so if possible, always try to use fresh air and fragrance free product.
    • Advantage: cheap and easily accessible
    • Disadvantage: natural smells like fecal matter does not smell good.


Different variations of improving indoor lighting[9]
  • Use natural lighting over artificial lighting
    • Design and construct indoors according to the rotation of earth around sun, so that people rise up with bright lights in their bedrooms and study rooms.
    • Advantage: very good for the biological clock of human body and easily accessible through utilizing passive solar design.
    • Disadvantage: once any building is built, changing the construction of existing rooms will be difficult.
  • Use adequate artificial lighting at night
    • The desired lighting effects are very different for different applications, so design and utilize artificial light wisely to create the atmosphere you need.
    • Advantage: adding new lights like lamps could be very easy and accessible
    • Disadvantage: adding new lights like fixed ceiling lights could be a lot more difficult.
  • Design and construct light reflectance indoor ceilings, wall, and floor surfaces[10]
    • Light reflectance surfaces allow a better overall space illumination, allowing for fewer light fixtures, and lower electrical cost.
    • Advantage: If light reflectance surfaces are available, the need for other light adjustment is minor.
    • Disadvantage: changing indoor surfaces could be inconvenient and costly.

Different variations of improving indoor acoustics[11]
  • Use canopies and suspended ceilings
    • Construct canopies and suspended ceilings to allow sound distribution and absorption evenly in rooms and between rooms.
    • Advantage:
    • Disadvantage:
  • Use absorptive material for construction [12]
    • Construct the house with absorptive material to absorb sound
    • Advantage: more cost effective than reflective material
    • Disadvantage: cost of installation and materials are higher still than regular walls
  • Use reflective material for construction
    • Construct the house with reflective material to reflect sound
    • Advantage: is more capable of mitigating loud noises
    • Disadvantage: cost of installation and materials are higher than regular walls and absorptive material

Different variations of improving indoor thermal comfort [13]
  • Use proper circulation to diffuse heat and air thoroughly
    • install low-e window film to reduce heat escaping in the winter and heat entering in the summer
    • Advantage: allow for better outdoor view
    • Disadvantage: installation and material is more costly.
  • Set temperatures according to different seasons[14]
    • Winter temperature better set at below 73.4 F, and summer temperature better set at above 73.4 F.
    • Advantage: make sure the productivity of workers
    • Disadvantage: hard to satisfy everyone's preference for desired temperature

Different variations of improving connecting indoors to outdoors[15]
  • Make physical change to the environment
    • Physical change like building a patio and porch can greatly increase inhabitants' connection to outdoors.
    • Advantage: the best connection to outdoors if option is available
    • Disadvantage: will require more lands and money
  • Make visual change to the the environment
    • Visual change like building big windows and french doors can also help inhabitant to feel more connected to outdoors
    • Advantage: the more available and practical approach of trying to connect to outdoors
    • Disadvantage: having big windows and French doors can be dangerous for people living in the city



IEQ in Construction Application


While designing and constructing a building with good indoor environment is important, making indoor environmental improvement to existing buildings is also possible. [16] There are a few ways to improve Indoor environmental quality during the construction process.
  • Only select odorless and safe materials for construction
  • Design windows and spaces for basic human desires and needs as much as possible
  • Understand thermal and moisture dynamics as a key part of selecting wall and roof assemblies
  • Make sure to construct air ventilation system

The following video shows a successful implementation of sustainable practice of St. John's hospital in Denver, Colorado.


Recent Research


Much recent research is done to help improve indoor environmental quality. For example,
1.
thermmodel3.jpg
The software output indicates overall comfort and sensation

The Advanced Thermal Comfort Model


This computer software, which was initially created for improving comfort in cars, is hoping to
include the capability to model the indoor environment in detail, allowing for prediction of comfort and thermal perception, for the body overall, and for specific body parts. [17] By better understanding thermal and occupant response to the environment can greatly help building owners in gaining a better market.


2.

Acoustical Field Study in a UFAD Building

A field study that is designed to quantify the amount of sound transfer in an office environment with an underfloor air distribution (UFAD) system. Noise, as the most prominent factor for annoyance in offices, is demanding for a better solution. This study represents acoustical measurements in a building with an underfloor ventilation system designed to meet the needs of a particular client.

ufad_septum_detail.jpg
Acoustical septum installed bellow for speech privacy in offices

3.

Occupant Perspectives on Outdoor Noise in Office Buildings


This is an ongoing research on how people prefer outdoors noise over indoors noise and windows over sealed walls.

4.

The Impact of Ventilation on Productivity


This study aimed to discover the relationship between ventilation of air and productivity of workers. Given that 90% of expenses are employee salaries, companies really want to improve employee's productivity by providing good ventilation at work.
  1. ^ Wu F., Jacobs D., Mitchell C., Miller D., Karol M. (2007). "Improving Indoor Environmental Quality for Public Health: Impediments and Policy Recommendations." <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892115/#b24-ehp0115-000953> (Dec. 3 2013).
  2. ^ DGS. Indoor Environmental Quality. California Sustainable Design Training.
  3. ^ WBDG Sustainable Committee. (2013). "Enhance Indoor Environmental Quality (IEQ)." <http://www.wbdg.org/design/ieq.php> (Dec. 3 2013).
  4. ^ Sundell J. (2004). "On the History of Indoor Air Quality and health." Indoor Air 2004., 14 (Suppl 7):51-58. <http://web.ebscohost.com.research-db.letu.edu/ehost/pdfviewer/pdfviewer?vid=6&sid=7574b98e-4ca8-4d59-993b-e373751c4ee2%40sessionmgr112&hid=119> (Dec. 3 2013).
  5. ^ Wu F., Jacobs D., Mitchell C., Miller D., Karol M. (2007). "Improving Indoor Environmental Quality for Public Health: Impediments and Policy Recommendations." <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892115/#b24-ehp0115-000953> (Dec. 3 2013).
  6. ^ Wu F., Jacobs D., Mitchell C., Miller D., Karol M. (2007). "Improving Indoor Environmental Quality for Public Health: Impediments and Policy Recommendations." <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892115/#b24-ehp0115-000953> (Dec. 3 2013).
  7. ^ Sundell J. (2004). "On the History of Indoor Air Quality and health." Indoor Air 2004., 14 (Suppl 7):51-58. (Dec. 3 2013).
  8. ^ Davis J. L. (2009). "Breathe Easy: 5 Ways to Improve Indoor Air Quality." < http://www.webmd.com/lung/features/12-ways-to-improve-indoor-air-quality > (Dec. 3 2013).
  9. ^ CBE Industry Consortium, Research Grants. (2008). "Advance Human Thermal Comfort Model."< http://www.chroniclejournal.com/publications/horizons/issues/2012/june/articles/improve-indoor-lighting-and-mood > (Dec. 3 2013).
  10. ^ Armstrong. (2013). "Indoor Environmental Quality." <http://www.armstrong.com/commclgeu/eu1/uk/gb/environment_indoor_environment_quality.html> (Dec. 3 2013).
  11. ^ Armstrong. (2013). "Indoor Environmental Quality." <http://www.armstrong.com/commclgeu/eu1/uk/gb/environment_indoor_environment_quality.html> (Dec. 3 2013).
  12. ^ Stacey M. "Sound Walls: Absorptive versus reflective design and effectiveness." <http://faculty.cs.byu.edu/~seamons/SoundWalls.pdf> (Dec. 3 2013)
  13. ^ Vista Window Films Blog. (2013). "Ways to Improve Thermal Comfort." <http://blog.vista-films.com/2013/05/improve-thermal-comfort/> (Dec. 4, 2013).
  14. ^ Lawrence Berkeley National Laboratory. (2013). "National Benefit of Better Control of Indoor Temperatures." <http://energy.lbl.gov/ied/sfrb/benefits-temps.html> (Dec. 4 2013).
  15. ^ Ann Robinson and Annie V. Schwemmer. (2009). "Renovation Solutions: Improving Indoor-Outdoor Connections." <http://www.deseretnews.com/article/705295407/Improving-indoor-outdoor-connections.html?pg=all> (Dec. 3, 2013).
  16. ^ WBDG Sustainable Committee. (2013). "Enhance Indoor Environmental Quality (IEQ)." <http://www.wbdg.org/design/ieq.php> (Dec. 3, 2013).
  17. ^ Center for the Built Environment. (2008). "Advanced Human Thermal Comfort Model." <http://www.cbe.berkeley.edu/research/briefs-thermmodel.htm> (Dec. 3 2013)